Help! Svt to Blk top conversion..

olskool

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Hi All,

Recently did the svt to blk top conversion at a shop.

Now my rpm is at 1.3-5k rpm..any idea why? Below is what I can see the mech did..

a) The Map sensor and Air temp sensor is connected to the AFM connector

b) Added one wire from compressor to the a/c valve controller removing the old one..

Still using svt wiring but changed to blk ECU, MAP n air temp sensor..

Thanks in advance..:itsme:
 

TRD.AE92

500 RPM
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Apr 10, 2009
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Hi All,

Recently did the svt to blk top conversion at a shop.

Now my rpm is at 1.3-5k rpm..any idea why? Below is what I can see the mech did..

a) The Map sensor and Air temp sensor is connected to the AFM connector

b) Added one wire from compressor to the a/c valve controller removing the old one..

Still using svt wiring but changed to blk ECU, MAP n air temp sensor..

Thanks in advance..:itsme:
a. because you kacut the wiring and ecu, so hard to identify too!
b. because you kacut the wiring and ecu, so hard to identify too!

So for easy up the task, why don't you just brought a BT wiring loom?
 

TRD.AE92

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olskool

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I noticed that on the brake booster side there's a black socket that blk top wiring doesn't have...what do you do with that?

---------- Post added at 04:08 PM ---------- 6 hour anti-bump limit - Previous post was at 10:43 AM ----------

Update:

a) a/c off, start car and let it run idle at 1.5k rpm, water temp MUST reach 82C an then it'll drop to 900-1k rpm.

b) start car, a/c on, temp can't reach 82C so idle always at 1.3-1.5k rpm

c) start car, a/c off, idle at 1.5k till 82C and above then it'll drop to 900-1.5k. On a/c (both fans on) temp will drop to 80 and idle will kick up to 1.5k rpm again..

I'm certain that it has something to do with the auto choke. Will check and update later...
 

cuscostrutbrace

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Wiring is just wiring,it is a medium to conduct electricity,AFM to MAP can idle properly if done correctly,even with SVT wiring...
 

TRD.AE92

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Wiring is just wiring,it is a medium to conduct electricity,AFM to MAP can idle properly if done correctly,even with SVT wiring...
Yes.. you are right too... But why heck up the time, brain and money?
If done properly sure can go without problem, but another problem is wiring man itself not wiring... Because not many people know how to convert too.
 

cuscostrutbrace

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The main problem when converting SVT to BT is the A/C control,even if you buy BT wiring+ECU (so called plug and play),the A/C issue is not resolved,the compressor will not engage properly..some wireman does not know this,hence they pull one new wire to run the A/C compressor.Also idling control when A/C on or off is different between SVT and BT.

Nowadays car A/C compressor clucth is controlled by the engine ecu,engine ecu will receive signal from another A/C ecu.For SVT and BT,the signal coming from the A/C ecu is different,i have a way around that,its called cheating..but i'm planning to make so converter circuit for this,not yet done,not enough time to develop...maybe Sifu Wong can help me,hehe.

Also O2 sensor SVT and BT is different,i have a way round that too however in theory it wont work unless change to BT O2 sensor,but so far no complaints and no check light come out.Discuss with Sifu Wong bout this and he has clarify things up,and come into conclusion the SVT O2 sensor can be used,but it is better to change to BT O2 sensor..

---------- Post added at 09:05 AM ---------- 6 hour anti-bump limit - Previous post was at 08:57 AM ----------

Well said ..
How come you 300hp+nitrous member,i dont have nitrous,no wonder la hard to catch in SIC ...:biggrin:

Hows your tuning?
 

km_chew

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The main problem when converting SVT to BT is the A/C control,even if you buy BT wiring+ECU (so called plug and play),the A/C issue is not resolved,the compressor will not engage properly..some wireman does not know this,hence they pull one new wire to run the A/C compressor.Also idling control when A/C on or off is different between SVT and BT.

---------- Post added at 09:05 AM ---------- 6 hour anti-bump limit - Previous post was at 08:57 AM ----------



How come you 300hp+nitrous member,i dont have nitrous,no wonder la hard to catch in SIC ...:biggrin:

Hows your tuning?
Yea, i'm running a separate aircond switch too .. your car won't drop a sweat if you are chasing me .. lolx ..

Haven't start, promise to send you a picture of the wiring 1st . Before April, would want it to settle by then.
 

cuscostrutbrace

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Yea, i'm running a separate aircond switch too .. your car won't drop a sweat if you are chasing me .. lolx ..

Haven't start, promise to send you a picture of the wiring 1st . Before April, would want it to settle by then.

Dont need to run separate a/c switch la,hehe..

OK no prob,want to know the result too..i love R&D..

Now i'm doing R&D to use Coil On Plug on our 20v with stock ECU,recent test with Waste spark was success,but have some issue with ignition timing,need to research more :biggrin:
 

cuscostrutbrace

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Can we replace SVT's aircon control box with BT's to resolve the issue?
Maybe can if it has the same connector and pin arrangement.Speaking of which,i would like to request you to take some voltage readings of your AE101 A/C control box (A/C amplifier) pin output,especially the one going to the ecu.(AC1,AC2,ACT),in various conditions like A/C on/off,blower on/off etc...i'll take some readings from a BT A/C amplifier and maybe we can work out to solve this issue.

I have one thing in mind now about the circuit to convert the signals but not yet to try..
 

cuscostrutbrace

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Jul 10, 2004
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What is the differences, ECu controlled aircond and non ECU controlled aircond ar?
Nowadays car A/C all related with the engine ecu.The A/C system place a huge load on the engine,and this robs power,fuel economy,engine running conditions,etc...the ecu will try compensate for this.Hence it need to know when the driver switch the A/C on,besides other engine running parameters during A/C usage.

This is where the A/C amplifier do its job to interface between the A/C controls input,ecu and its component output(compressor).When we switch A/C on,the ecu need to cater for the load demand,by adjusting the fueling,idle speed increase,ignition timing adjust.The ecu also tells when to switch the compressor on or off depends on situation,like overtaking,where the engine need more power.The A/C amplifier will regulate temperatures,compressor controls,blower motor controls etc (during Auto mode)

Without ecu controlled aircon,it doesnt do all the above.
 

km_chew

Known Member
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Aug 10, 2004
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Nowadays car A/C all related with the engine ecu.The A/C system place a huge load on the engine,and this robs power,fuel economy,engine running conditions,etc...the ecu will try compensate for this.Hence it need to know when the driver switch the A/C on,besides other engine running parameters during A/C usage.

This is where the A/C amplifier do its job to interface between the A/C controls input,ecu and its component output(compressor).When we switch A/C on,the ecu need to cater for the load demand,by adjusting the fueling,idle speed increase,ignition timing adjust.The ecu also tells when to switch the compressor on or off depends on situation,like overtaking,where the engine need more power.The A/C amplifier will regulate temperatures,compressor controls,blower motor controls etc (during Auto mode)

Without ecu controlled aircon,it doesnt do all the above.
If that is the case, then mine is connected to the ECU already. Because the auto function works. Temperature, directional, working too. Not sure why there is extra button for the On / Off instead of using the original panel.

Pardon my noob query. Another new thing to learn for today. :itsme:
 

cuscostrutbrace

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Jul 10, 2004
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If that is the case, then mine is connected to the ECU already. Because the auto function works. Temperature, directional, working too. Not sure why there is extra button for the On / Off instead of using the original panel.

Pardon my noob query. Another new thing to learn for today. :itsme:
I'm also noob,hehe..lot more things i dont know,i might be wrong as well on some things i said,so dont flame me,we learn together..

The auto function will work but your compressor is not when you change to BT wiring,thats why the extra On/off button..Its the signal to ecu is different,but the auto function is not.

The communication is like this,A/C Switches/controls <-> A/C Amplifier <-> ECU
 
Last edited:

olskool

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Jan 15, 2005
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Wow!!! And they told me "SVT change to MAP very easy one...Just join wires only.." LOL..

Thanks to all for this new and breaking input. I initially just wanted to get rid of the occational dying situation but what to do...itchy wanna do MAP..
 

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